libcamera: pipeline_handler: Fix incorrect method in CameraData docs

The pipeline handler documentation incorrectly references an old API
usage of setCameraData, which should have been updated to
registerCamera() while updating pipeline handlers to ensure they all
have a pipeline-specific "CameraData" allocation.

Update the remaining documentation reference.

Fixes: b581b9576a ("libcamera: pipeline_handler: Make pipeline-specific data mandatory")
Signed-off-by: Chris Chinchilla <chris@gregariousmammal.com>
Reviewed-by: Umang Jain <email@uajain.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Kieran Bingham <kieran.bingham@ideasonboard.com>

src/libcamera/pipeline_handler.cpp

@@ -46,7 +46,7 @@ LOG_DEFINE_CATEGORY(Pipeline)
  *
  * Pipeline handlers are expected to extend this base class with platform
  * specific implementation, associate instances of the derived classes
- * using the setCameraData() method, and access them at a later time
+ * using the registerCamera() method, and access them at a later time
  * with cameraData().
  */